XECOM XEV90C-ITR, XEV90C Datasheet

XECOM (1) XEV90C

XEV90C

June 2000

Figure 1: XEV90C BLOCK DIAGRAM

Line

Transformer

Line Current

Holding

Circuit

Hookswitch

Ring

Detector

T1

T2

OH(+)

Tip

Ring

Low

Impedance

Dialing

MUTE(-)

Description

Xecom’s XEV90C is a complete, multi-national DAA
integrated into a compact PLCC package. The XEV90C
supports analog data transfer to 56 KBPS and complies
with both FCC Part 68 Rules and the Pan-European
CTR21 specifications. The modified 68-Pin PLCC
package permits automated, high-volume assembly.

The XEV90C does not sacrifice performance for small
size and surface-mount convenience. The heart of the
XEV90C is a proprietary, low profile, low distortion
transformer. This wide bandwidth, low distortion device
provides the clear signal path required for 56 KBPS
analog data transfer.

The XEV90C is a complete telephone line interface. It
includes the telephone line transformer, line current
holding circuit, Caller ID Passthrough circuit,
hookswitch and ring indicator with line connect detect.
The XEV90C replaces the dozens of components found
in discrete and transformerless DAA designs.

Features

* Package: Thick 68-Pin PLCC (only 18 pins used)

dimensions 0.952 inches by 0.952 inches by 0.290
inches high

* Meets Total Harmonic Distortion requirements for

reliable 56 Kbps modems (-85 dB typical)

* Integrated Low-Distortion T elephone Line

Transformer

* Integrated Ring Detect with Line Connect Detect

capability
* Integrated Caller ID Passthrough Circuit
* Operates on a single Power Supply of +5 Volts
* Solid-State Hookswitch Control with active high

and active low inputs
* FCC Part 68 and CTR21 Compliant;
* Extended Temperature Range available, order part

number XEV90C-ITR;

OH(-)

RI(-)

DC2
DC1

Caller ID

Bypass

CAP1
CAP2

PLCC Packaged DAA for Europe and North America

XECOM (2) XEV90C

Figure 2: XEV90C Pin Configuration

1
2
3
4
5
6
7
8
9

18
17
16
15
14
13
12
11
10

RI(-)
N/C
OH(+)
T1
T2
/Mute
OH(-)
VCC
Gnd

CAP1

Ring

Tip
N/C
N/C

CAP2

N/C

DC1
DC2

XEV90C

(top)

XEV90C Pin Descriptions

PIN NAME DESCRIPTION

1 CAP1 CAP1 provides a connection point for the external blocking capacitor on the XEV90C. Two

forty microfarad capacitors must be placed between the CAP1 and CAP2 pins for 56 KBPS
performance. Twenty microfarad capacitors can be used for lower data rate applications.
These polarized capacitors must be placed back-to-back to block line battery voltage of either
polarity. These capacitors must be rated at 50 volts for CTR21 applications and 10 volts if
CTR21 compliance is not required.

A 5 milliHenry inductor may be placed in series with the blocking capacitors to compensate for
the German billing tone filter. This filter is not addressed in CTR21 but is recommended for
applications destined for Germany to prevent interference with communications.

2 Ring Along with the Tip signal, Ring provides the connection to the telephone line. FCC Part 68

Rules require a 1500 volt isolation barrier between the telephone line and all other circuits. This
isolation must be preserved throughout the system.

The telephone company places a DC “Battery” voltage across Tip and Ring on all public switched
telephone lines. The XEV90C will operate regardless of the polarity of this “Battery” voltage.
The “Battery” voltage drives up to 100 milliamps of DC loop current.

UL1950 requires minimum creepage and clearances distances be maintained between the Tip
and Ring traces and all other circuits. Clearance is the shortest distance between conductive
circuits; creepage is the distance between conductive surfaces along the surface.

3 Tip Along with the Ring signal, Tip provides the connection to the telephone line. FCC Part 68

Rules require a 1500 volt isolation barrier between the telephone line and all other circuits.
This isolation must be preserved throughout the system.

4 - 5 No Connection

6 CAP2 CAP2 provides a connection point for the external blocking capacitor on the XEV90C. Two

forty microfarad capacitors must be placed between the CAP1 and CAP2 pins for 56 KBPS
performance. T wenty micro-farad capacitors can be used to meet lower data rate applications.
These polarized capacitors must be placed back-to-back to block line battery voltage of either
polarity.

XECOM (3) XEV90C

7 No Connection
8 DC1 DC1 and DC2 control the performance of the loop current holding circuit. A jumper between

DC1 and DC2 limits the DC loop current to 60 milliamps as required for CTR21. An open
circuit between DC1 and DC2 allows loop currents up to 100 milliamps as required for North
America and Japan. A resistor may be placed between DC1 and DC2 to adjust DC off-hook
impedance to meet unique country requirements.

9: DC2 DC1 and DC2 control the performance of the loop current holding circuit. A jumper between

DC1 and DC2 limits the DC loop current to 60 milliamps as required CTR21. An open circuit

between DC1 and DC2 allows loop currents up to 100 milliamps.
10 Ground Ground provides the reference voltage for all host interface signals.
11 VCC VCC provides operating power to the XEV90C. VCC must equal five volts plus or minus 10

percent.
12 OH(-) OH(-) controls the switch-hook within the XEV90C with an active low input. If the user wishes

to use an active high device to drive the switch-hook, Pin 16 provides the active high switch-

hook control. Activating OH(-) closes the internal switch-hook and seizes the local telephone

line. OH(+) must remain open when OH(-) is in use.
13 Mute(-) Mute(-) provides an active low input for low impedance pulse dialing or for meeting the

minimum transitional impedance required by CTR21. Presenting a low impedance while pulse

dialing is a requirement of several European countries including, Germany, France and Italy.

CTR21 does not regulate pulse dialing. European pulse dialing requirements continue to be set

by the individual countries.
14 T2 T2 in conjunction with T1 provides the differential input/output for the analog signal.
15 T1 T1 in conjunction with T2 provides the differential input/output for the analog signal.
16 OH(+) OH(+) controls the switch-hook within the XEV90C with an active high input. If the user

wishes to use an active low device to drive the switch-hook, Pin 12 provides the active low

switch-hook control. Activating OH(+) closes the internal switch-hook and seizes the local tele-

phone line. OH(-) must remain open when (OH+) is in use.
17 No connection
18 RI(-) RI(-) indicates the presence of an incoming ring (Ring Indication) or a drop in the Battery

Voltage on the local telephone line (Connect Detection). RI(-) is an active low signal. RI(-)

provides a square wave representation of the ring signal present on the telephone line. This

permits the host to intelligently monitor the local telephone line.

RI(-) also communicates the availability of the local telephone line with the Connect Detect

Feature. When the Battery Voltage on T ip and Ring drops below twenty volts, RI(-) switches to

high level to indicate the local telephone line is not available for use.

XEV90C Pin Descriptions (continued)

PIN NAME DESCRIPTION

XECOM (4) XEV90C

XEV90C Electrical Specifications (Vcc=+5v ±10%, Ta=0 to 70 deg C)

Power Supply Current Off-hook 10 mA

On-hook 0.5 mA
Transmit Insertion loss 600 Ohm Impedance, 1800 Hz 2 3.5 5.0 dB
Receive Insertion loss 600 Ohm Impedance, 1800 Hz 3.5 5.0 6.5 dB
Caller ID Insertion Loss Hookswitch Open 10.0 11.5 13 dB
Line Matching Impedance Input to T1 and T2 300 340 37 0 ohms
Line Impedance 370 ohm matching impedance resistor 540 600 660 ohms
Total Harmonic Distortion 600 Ohm Impedance, 100 to 4000 Hz -80 -85 dB
Ring Detect Sensitivity Min. AC voltage between Tip & 20 150 Vrms

Ring Type B ringer
Ring Frequencies Detected 16 68 Hz
RI Output Voltage Ring signal present, Active low 0.2 0.5 Volts
Hook-Switch Control ON: (off-hook) 0.2 0.5 Volts
Voltage (active high) OFF: (on-hook) 2.0 3.0 Volts
Hook-Switch Control ON: (off-hook) 2.0 3.0 Volts
Voltage (active low) OFF: (on-hook) 0.2 0.5 Volts
Hook-Switch Control ON: (off-hook) 5 10 milliamps
Current OFF: (on-hook) 5 microamps
Loop Current No Connection from DC1 to DC2 0 10 0 mA
(current draw from line) DC1 shorted to DC2 0 60

DC On-Hook Impedance Hookswitch Open 10 MOhms

Parameter Conditions Min Typ Max Units